Disclosed are methods for preparing a mixture of eight diasteromers of vittatalactone
Also disclosed are mixtures of eight diasteromers of vittatalactone produced by the methods described herein. In addition there are described compositions comprising a mixture of eight diasteromers of vittatalactone and optionally 2E,6Z-nona-2,6-dienal
and optionally cucurbitacin B or cucurbitacin B wherein the bond between carbons 1 and 2 is replaced with C═C, or cucurbitacin B wherein OH is attached to C25, or cucurbitacin B wherein the bond between carbons 1 and 2 is replaced with C═C and OH is attached to C25, or cucurbitacin B wherein the bond between carbons 1 and 2 is replaced with C═C and OH is attached to C25 and the bond between carbons 23 and 24 is C—C, or cucurbitacin B wherein OH is attached to C25 and the bond between carbons 23 and 24 is C—C, and optionally a carrier. Furthermore, there are describe methods of attracting Acalymma vittatum to an object or area, involving treating said object or area with a Acalymma vittatum attracting composition containing a Acalymma vittatum attracting effective amount of the compositions described herein. The methods, mixtures, and compositions described herein exclude the following 24 diastereomers:

Vegetable crops are an important commodity in the United States. These crops include cucurbit crops (e.g., squash, melons, cucumbers, pumpkins) (Cavanagh, A., et al., J. J. Econ. Entomol., 102: 1101-1107 (2009)). The main insect pest of these cucurbit crops is the striped cucumber beetle, Acalymma vittatum (Coleoptera: Chrysomelidae), which also serves as the vector for Erwinia tracheiphila, a bacterium that causes a lethal wilt disease in cucurbits (Garcia-Salazar, C. G., et al., Environ. Entomol., 29: 542-550 (2000); Garcia-Salazar, C. G., et al., Can. Entomol., 132: 1-13 (2000)). There is high demand for sustainable plant protection since classical use of insecticides can be extremely expensive and additionally impacts pollinators and natural enemies of Acalymma vittatum. 
The composition of the pheromone mixture secreted by the feeding male beetles contains a main component vittatalactone accompanied by a minor compound 12-norvittatalactone (Morris, B. D., et al., J. Nat. Prod., 68: 26-30 (2005)). Both vittatalactone and 12-norvittatalactone contain five stereogenic centers, representing the most complex structures among physiologically active insect volatiles. The total synthesis of the enantiomer of vittatalactone based on an iterative allylic substitution concept was reported in 2009 (Schmidt, Y., and B. Breit, Org. Lett., 11: 4767-4769 (2009). By means of the enantiomer synthesis, the absolute configuration of the natural product was elucidated, and the total synthesis, the determination of the absolute configuration of vittatalactone through total synthesis of two eventual diastereomers, and the synthesis of the natural enantiomer of vittatalactone was reported in U.S. Patent Publication No. 2011/0282075. Since the identification of vittatalactone as male produced pheromone of cucumber beetles, there are at least three published synthesis of natural vittatalactone in the last seven years. However, due to complex synthesis and production of the vittatalactone in milligram quantities (10 to 90 mg), neither laboratory evaluation nor semi-field trials were initiated.
Thus there is a need to find economically viable attractants and hence practical solutions to manage cucumber beetle. Herein we present novel semispecific synthesis of eight diasteromers of vittatalactone, the composition comprising mixed products (eight diasteromers) of which are surprisingly highly attractive to both sexes of A. vittatum under laboratory conditions and in a short field study in vegetable plantings confirmed high attraction of A. vittatum to the economically viable synthetic mixture of vittatalactone diasteromers.